Chara

While chara was still a mourning spirit she saw horrible things, the once friendly monsters of the ruins killing and devouring each other even though, she was twisted and evil chara was still a child and she actually felt fear of these creatures for the first time.

Once chara became corporel she tried to, help them and maybe bring back some of their sanity but with every try, she failed this slowly broke away at her faith, in fixing the underground one day her body glitched bringing her back from the dead but as another predator of the ruins.

Her hands were transformed into deadly blades, her eye’s dark and lifeless a mysterious black liquid usually leaks from her eyes and mouth, now chara doesn't care about fixing the underground anymore she only wants to hunt.

even though she is incredibly powerful she stays in the ruins since, a certain skeleton would “love” to reunite with her she has no fear in the ruins most monsters “try” to run away, but she will always find them chara usually hunts with flowey but if the food source runs out she's hunting him.

Hunger form:
If chara can’t find food or if she gets really annoyed, she turns into a horrible beast her blade hands duplicate turning into deadly claws, her jaws expand to be able to swallow prey whole, her body usually gets torn apart in this transformation, but gets replaced with the black liquid this form will hunt anything, that moves so it's best not to get in her way.